Loop aerial



June 30, 1931. ARM 1,812,695

LOOP AERIAL Filed April 12, 1926 3 Sheets-Sheet 1 fv/v 728E fliezi c2fir/77;,

June so, 1931. A M 1,812,695

LOOP AERIAL Filed April 12, 1926 3 Sheets-Sheet 2 June 30, 1931. G,HARMS 1,812,695

LOOP AERIAL il April 1926 3 Sheets-Sheet 3 z 1 9%M ww Patented June 30,1931 PATENT OFFICE ALBERT G. HARMS, OF CHICAGO, ILLINOIS LOOP AERIALApplication filed April 12, 1926. Serial No. 101,325.

My invention has reference to loop aerials such as are used inconnection with radio receiving sets or other similar apparatus forcollecting electrical waves in radio or wireless communication.

The invention relates to that type of loop aerial shown and described inmy co-pending application, filed December 24:, 1925, under Serial No.77,568, and more particularly to that type having an area about whichthe wires are wound to wholly enclose said area or a substantiallycontinuous winding throughout the entire area, field, or surroundingsides thereof but embodies in addition,

a novel loop aerial in which a series of substantially independent loopsare disposed one within the other in fixed or movable relation andespecially wherein said loops are rotatable one with respect to theother to vary their angular relation when movable relatively, and inwhich said loops or the loop as an entirety embodying a series of loopsdisposed successively one within the other, are adapted to be connectedelectrically or inductively and in parallel, series or multiple forvarious purposes, as will be hereinafter more fully set forth, such asfor disposing them in a relation to produce a variable inductance forincreasing or decreasing the signal strength, tonal quality, or clarityof the reception; for tuningin or out certain waves of different lengthsin the manner of a trap that is, different stations; for varying thelength of wire in the coils, the number of coils embodied in the deviceas a whole and its flexibility or scope of reception and tuning abilityor qualities, as well as the relative lengths, sizes, and inductances ofthe coils or windings of the coils and for other useful purposes andadvantages as will be apparent as the description proceeds.

In the accompanying drawings Fig. 1 is an elevation of a loop aerialembodying principles of my invention and illustrating the same in onesingle form.

Fig. 2 is a top plan view of the device as shown in Fig. 1 with one formof winding.

Fig. 3 is a top plan view of a form in which the inner or auxiliaryloops or windings are movable angularly or rotatably with respect to anouter loop or winding or any of the windings outwardly thereof andshowing an inner loop or winding shifted with respect to an outer one.

Fig. 4 is a diagrammatic elevation showing 57.3 the loops or windingsconnected in series.

Fig. 5 is a diagrammatic perspective view showing the relation of theloops when mounted one within the other in fixed or movable relation,and

Fig. 6 is a diagrammatic elevation similar to Fig. 4 but showing theloops connected in multiple.

Referring to the drawings in detail, 7 indicates abase on which theaerial or radio antenna 8 is mounted, preferably to turn as by means ofa frame including an upright 9 having a pivot portion engaged in asocket 10 in the base. The upright 9 may have a series of successivelyreduced portions or tubes 11 forming shoulders 12 against which endmembers 18 in the form of suitable plates or disks of rectangular orother shape are secured either in fixed relation or in such a mannerthat the top and bottom end members of the frames or opposed pair ofplates may be turned or rotated one within the other in differentangular relation. The plates 13 are preferably provided with notches orother receiving means 1-1 for continuous windings or coils 15 of aplurality of loops or windings placed one within the other, the seriesof loops forming a single loop aerial in its entirety. If preferred, theplates 18 may be arranged in any other suitable relation or in contact,35 and the coils 16 thereof are preferably extended diagonally of therespective plates or frames and may be arranged with the leads orextremities thereof free, as indicated at 17 in Fig. 2 of the drawings,or may be connected in series .as indicated at 18 in Fig. 4 of thedrawings or in multiple or parallel, as shown by theconnections 19 inFig. 6 of the drawings.

The coils of the respective loops 15 may be equi-distantly spaced apartas shown in Figs. 1, 2, and 3, in which event the inductance of therespective loops placed one within the other vary, owing to thedifferent lengths of wire carried thereby, the inner loops being smallerand of less inductance than the outer loops, so that the loops are ofprogressively less inductance inwardly and of greater inductanceoutwardly. While the loops may be maintained in fixed relation withtheir coils all extending in the same direction as shown in Figs. 1 and2, or otherwise, they may be arranged at any other desired angularrelation and when arranged to turn relatively, may be disposed indifferent angular relations as illustrated in Fig. 3. All of the loopsare of the type wherein the windings extend substantially entirelyaround the field or loop as shown and de scribed in my prior applicationabove alluded to, the loops being parallel and progressively decreasingin width from the center to the opposite sides 01' increasing in widthand-size from opposite sides to the center in opposite directions, inaddition to being disposedclosely adjacent. \Vhile I have shown notchesfor receiving the wires on the respective end members or plates 13, itis to beunderstood that any other suitable wire-receiving and retainingmeans for the windings may be provided.

In Fig. 3 of the drawings one of the inner loops is shown turned withrespect to the adjacent outer loop for the purpose of raising orlowering the inductance value and for tuning as in connection with avariometer. Alternate loops may be connected inductively orelectrically, according to the result to be obtained. If all of theloops are connected inductively, the inductance, of course, will begreater and where alternateloops are connected inductively andelectrically, for instance, the outer and third inner loop of theplurality of loops composing the aerial may be inductively connected andthe second and fourth or other loops electrically connected to assist inenergizingthe inductively connected loops and increasing the inductiveeffect by catching the waves and transmitting the same to theinductively connected loops.

This provides for greater signal strength and clearer andsharper tonequalities. This, as well as the arrangement of having the loopsadjustable angularly, serves the purpose of tuning by bucking ,orcutting in or out one or more stations after tuning the same in orbyarrangingthe loops or coils in such a manner as to reduce theinductance. W'hen the coils are connected in multiple, the inductancebalances, being an average of the four, five,

or other number of loops which may be em.-

the latter case shown more especially in Fig.

5, the windings are closer together as they approach the inner-loop. Inthis way, the same length of wiring may be arranged in each loop owingto the coils or windings thereof being closer together as the loops areprogressively decreased in size. In this way the inductance of the loopsmay be made equal instead of being varied orprogressively' decreasinginwardly, this depending upon the length of wire or number of coils inthe respective loops. While I have shown the end members or plates 13spaced'apart, they may be arranged in other suitable relation and can bemade thicker and arranged in contact whether mounted in fixed relationor adapted to turn relatively, with the sam results as heretoforepointed out. While I have shown and described my .in-

vention in a preferred form, I am aware that" various modifications andchanges may be made therein without departing from the principles of theinvention, the scope of which is to be determined from the appendedclaims. It also has been found in practice that by placing a variablecondenser in shunt with one or more of the loops not electricallyconnected with the set, a broadcast station can be tuned in or tunedout, i; e. eliminated, by adjusting the condenser, that is, by varyingthe capacity of the condenser, thereby broadening the frequency range ofthe .loop to receive on higher or lower frequencies without tapping orcutting in or out parts orturns of the loop.

I claim as my invention: 7

1(A loop aerial having more than two loops mounted successively onewithin another in decreasing size and each having a continuouslyextending coil winding with the coils thereof equidistantly spaced apartin parallel relation and supported on successively enlarged portions.

2. A loop aerial having'at least four loops contained in spacedrelationone'within another, each loop having the coils relatively closely woundin spaced relation and extending entirely around the area thereof,succes-' sively enlarged posts fitting one within another and eachsupporting a loop. V

8. A loop. aerial including at least-four loops successively placed onewithin the other and having the wiring thereof extending continuouslyaround each on all sides in coils with the sides approaching each otherand the windings adapted to varying lengths, and for variable connectioninductively or in opposition each loop having a tube and the tubes beingsuccessively smaller to movably fit one within another whereby each loopmay be adjusted or turned on a vertical axis angularly with respect tothe other loops.

ALBERT G. HARMS.

